From plant waste to sustainable products

Atomic details unravelled for enzyme could help turn plant waste into sustainable products

Lignin is a tough polymer found in plant cell walls, and is the largest reservoir of renewable, aromatic carbon found in nature.
Through research at Diamond, a new enzyme family has been discovered which opens up avenues to converting plant waste into sustainable products, such as plastics, chemicals, and fuels.

The structure of the enzymes were explored using the Macromolecular Crystallography beamlines I03 and I04 here at Diamond. These enzymes are active on lignin, which scientists have been trying for decades to break down efficiently.

“To protect their sugar-containing cellulose, plants have evolved a fascinatingly complicated material called lignin that only a small selection of fungi and bacteria can tackle. However, lignin represents a vast potential source of sustainable chemicals, so if we can find a way to extract and use those building blocks, we can create great things.”

Professor McGeehan, Director of the Institute of Biological and Biomedical Sciences in the School of Biological Sciences at Portsmouth.
The research team have been able to overcome obstacles in the process of breaking down lignin to its basic chemicals. The results provide a route to making new materials and chemicals such as bioplastics and carbon fibre, from what is currently a waste product.
The discovery also offers additional environmental benefits – creating products from lignin reduces our reliance on oil to make everyday products and offers an attractive alternative to burning it, helping to reduce CO2 emissions.
The discovery was led by members of the same UK-US team which, in April, improved a plastic-digesting enzyme, a potential breakthrough for the recycling of plastic waste.
“This is another great example of how international collaboration can help make significant scientific progress. 

We are providing world-leading analytical tools to our user community and are clearly fulfilling our role as an agent of change on 21st century global challenges. It is fantastic that UK scientists and facilities are helping to lead the way.”
Prof Dave Stuart Life Science Director at Diamond Light Source and MRC Professor of Structural Biology at the Department of Medicine University of Oxford 

Two seperate enzymes interact to form a complex machine for modifying lignin monomers.